As service providers move forward with network optimization strategies, including congestion management, the need to ensure satisfactory customer quality of experience (QoE) will be critical.
High speed Internet customers no longer see the Internet as a platform for publishing and sharing static images. They are relying more and more on their service for entertainment, education and information, and their expectations of their broadband provider have increased as well. Therefore, the driving factors of rapid broadband deployment are the services that can be delivered on top of this technology. The services that are offered today go far beyond the best-effort services of a decade ago. The Internet technologies are being used to form an infrastructure that delivers data, audio and video traffic at the same time. QoE is essential for all these services. Multimedia services like IPTV are particularly sensitive to packet loss, delay and jitter, and often require a substantial amount of bandwidth, so a mechanism must be in place to detect QoE degradation and react appropriately to restore it.
Rapidly increasing video quality combined with rapidly increasing adoption, leads to traffic growth rates that put serious pressure on the network infrastructure. It is expected that IP traffic will double every two years. With broadband becoming ubiquitous, providing not only adequate but enhanced QoE will be the primary point of differentiation when it comes to customers' satisfaction and subscriber growth.
Existing research has identified key factors in customer experience that impact traditional best-effort broadband service QoE. Delay is one such factor. Delay refers to the initial system response time from providing URL until the end-user is aware that a download has started. The data download speed is frequently communicated to the end-user by means of a file transfer dialogue box that includes a numeric display of download status (% or number of bytes downloaded/total bytes) or by a network rate meter. The consistency of download speed is another factor that affects the customer experience. If the download is at a steady rate, then the user has a good idea (either intuitively or through a meter) of when it will finish. If on the other hand the rate varies greatly, then the finish time is much less certain and the user cannot plan how to use the intervening period so effectively. The incremental display factor is the time before there is some new, intelligible content to view. It is often the case that the display starts to update before the download is complete. As soon as the user has some new information to consider, the fact that the download is still in progress is of less importance. Action availability is the time before the user can undertake the next step in the browsing process, e.g., a new link or action button becomes useable. Again this may be before the download is complete. Finally, the absolute time until the download is complete has an impact on the customer experience.
Data associated with parameters of the network, such as such as jitter, latency, packet loss, signal power, signal quality, etc., are an objective measurement of the technical health of the network. However, the customer experience, i.e., quality of experience (QoE), should reflect the actual experience of the customer, not the measure of what is technically occurring on the network.
Moreover, even if individual quality of service parameters are correlated with aspects of the quality of experience of a subscriber, quantifying how to score the overall experience of a subscriber is still elusive. For example, providing a certain bandwidth may be very important to an actual customer experience, but the customer's response needs to be included in any quantification of QoE. Having a 40 megabit per second downloading capability is faster than having a 20 megabit per second, but if the customer does not see much of a difference, then the difference is not that important to the customer. What matters is how the customer is impacted.
Accordingly, there is a need for providing a framework for quantifying a total quality of experience for subscribers in a communications network.